1. Field
The inventive concept relates generally to semiconductor devices and methods of manufacturing the same, and more particularly, to semiconductor devices having a gate insulation layer including a high-k material and a diffusion barrier layer.
2. Description of the Related Art
In order to reduce a leakage current through a gate insulation layer of a transistor, a method of forming the gate insulation layer using a high-k material has been developed. However, when a gate electrode including polysilicon is formed directly on the gate insulation layer including the high-k material, the transistor may have an increased threshold voltage and decreased electron mobility due to the Fermi-level pinning effect. Thus, gate electrodes having a metal rather than polysilicon have been developed.